Magnetic fuel injection nozzle



Sept. 26, 1961 T. M. BALL MAGNETIC FUEL INJECTION NOZZLE Filed April 9,1958 INVENTOR. 720/774 54 ZZ,

BY H vwuuq'hlm Unitcd States Patent 3,001,757 MAGNETIC FUEL INJECTIONNOZZLE Thomas M. Ball, Bloomfield Hills, Mich., assignor to ChryslerCorporation, Highland Park, Mich, a corporation of Delaware Filed Apr.9, 1958, Ser. No. 727,484 3 Claims. (Cl. 251-140) This invention relatesto improvements in fuel injection nozzles of the type employed oninternal combustion engines.

Fuel injection nozzles of the aforesaid type are conventionallyinstalled on the intake manifold of internal combustion engines. In suchinstallations the nozzle is usually located in close proximity to theintake valve and is intended to deliver pulsations of fuel to the intakemanifold adjacent to the intake valve in response to electrical pulsestransmitted to the nozzle by a sensory system. The amount of fueldelivered to the manifold by each fuel pulsation is controlled by thenozzle which is in turn controlled by the engine operating conditions asinterpreted by said sensory system.

Fuel injection nozzles installed as aforesaid have, prior to myinvention, an inherent and most objectionable action in that they do notrespond instantaneously to electrical impulses sent by the sensorysystem and consequently do not deliver the exact amount of fuel requiredby the engine at any particular time. This gives rise to poor engineperformance through the improper fuel-air mixture delivered to theengine, and results inloss of power and fuel economy.

It is an object of my invention to provide an improved fuel injectionnozzle adapted for installation as aforesaid but which will overcome theabove objections.

Another object is to provide a fuel injection nozzle of simpleconstruction in relation to other nozzles 'known heretofore which, wheninstalled on an engine intake manifold, will operate efficiently inproviding the proper amount of fuel to the manifold as required by theengine at each instant of operation of said engine.

Another object is to provide a fuel injection nozzle with a valvecapable of opening and closing many times per second in response tomagnetic fields of very short duration created by an electrical coil anda sensory system, which sensory system supplies current impulses to saidcoil in response to engine fuel requirements.

Another object is to provide a fuel injection nozzle having a solenoidoperated valve wherein the valve closing means is a thin disc and has arelatively large surface area disposed in the flux path of saidsolenoid, so that the disc will be susceptible to the magnetic fieldsproduced by the solenoid coil and will respond practicallyinstantaneously to the magnetic fields to open said valve.

Another object is to provide a fuel injection nozzle having a solenoidoperated valve wherein the valve closing means is readily responsive tomagnetic fields produced by said solenoid and wherein the responsivenature of said valve closing means to magnetic fields permits the use ofrelatively weak magnetic fields in opening said valve.

In carrying out my invention I use a magnetically operated valve locatedwithin the injection nozzle. This valve comprises a port which is closedand opened by a thin, lightweight disc which responds very rapidly to aa magnetic field. The unique shape of this disc allows a relativelysmall electrical coil producing a low magnitude magnetic field to beemployed in moving said disc to an open position with respect to saidport. The use of this small coil avoids the excessive retention ofmagnetism by the coil and provides a sharply defined magnetic fluxcycle. This relatively low magnitude magnetic field also avoids thebuilding up of magnetism in the disc to a point which would retard thereturn of the disc to the port closing position at the termination ofthe energization of the coil. Asa result of this sharply defined, lowmagnitude flux cycle the disc is able to respond practicallyinstantaneously to the electrical pulse transmitted to the electricalcoil by the sensory system.

Further objects and advantages of my invention will be apparent from thefollowing detailed illustration thereof, reference being had to theaccompanying drawings, in which:

FIGURE 1 schematically shows an injection nozzle mounted on anautomotive engine and attached to various electrical components of thesensory system;

FIGURE 2 is a cross-sectional detail of the injector of FIGURE 1;

FIGURE 3 is a full section through 33 of FIG- URE 2;

FIGURE 4 is a cross-sectional detail of a variation of the injector ofFIGURE 1; and

FIGURE 5 is a full section through'55 of FIGURE 4.

In FIGURE 1 is shown a portion of an automotive cylinder block 6 havingreciprocably mounted therein a piston 8. A cylinder head 10 is mountedon said block and sealed thereto by gasket 12 and bolts (not shown).Mounted in head 10 is a spark plug 14, an intake valve 16, and a fuelinjection nozzle 18 having a fuel inlet line 9 extending thereto. Valve16 is reciprocable in bushing 20. An exhaust valve (not shown) is alsoreciprocably mounted in head 10. Fuel injection nozzle 18 iselectrically connected to triggering selector 22 by electrical conduit24.

Located on the triggering selector 22 are injector lead terminals 26,28, 30, 32, 34, 36, and 38, and two output terminals 40 and 42. The leadterminals are selectively energized within the triggering selector bymeans of a distributor rotor which selectively distributes the currentto brushes within the trigger selector housing which carry the currentto the lead terminals. Conduit 24 canies the triggering selector outputpulse current to the solenoid of the injection nozzle 18.

A modulator 44 receives energizing current from the triggering selector22 through conduit 46. A rotating lobe cam and two sets of breakercontacts within the triggering selector housing distribute energizingcurrent to the conduit 46. The modulator 44 carries its own distributingsystem and distributes energizing current to a resistance box throughconduit 48. This resistance box contains various resistances, theVoltages across which are affected by atmospheric and engine conditions.The changes in the voltages across these resistances are carlied to themodulator 44 through conduit 50 and are recorded in said modulator. Themodulator interprets these voltage changes and evaluates them in termsof the fuel requirements of the engine at the particular instant thatthe voltage variations are received in the modulator.

The evaluated fuel requirements are then converted in the modulator tocurrent pulsations of a length proportional to the engine fuelrequirements at that parto a lower housing portion 62. portion 62 arereceived in cooperating threads in engine head as shown in FIGURE 1.Secured to housing ticular instant. These pulsations are transmitted tothe triggering selector 22 by conduit 54. Suitable means within thetriggering selector, which may be a conventional rotor, picks up thesepulsations from the modulator and selectively distributes them to theindividual injector nozzle solenoids which are energized for a length oftime substantially equal to the length of the current pulsation receivedby the triggering selector from the modulator. Solenoid lead 56 isconnected at an appropriate place to the input side of the triggeringselector circuit.

In FIGURE 2 is shown a liquid fuel injection nozzle 58 having an upperhousing portion 60 threadedly secured Threads 64 on said portion 62 bythreads 66 is a valve body designated generally as 68. Recess 70 inhousing portion 62 slidably receives the enlarged head 72 of valve body68. A slot 74 is located in the reduced threaded end of valve body 68 toreceive a screw driver bit for adjustment of valve body 68longitudinally of housing portion 62. A seal ring 76 of suitable fuelcorrosion resistant material located in groove 78 of valve body 68creates a fluid tight seal between said body and housing portion 62.

An aperature or port 81 centrally located in body 68 provides a fluidpassage completely through said body and opens at the top end thereofinto a fuel receiving well 80 located in head 72 of said valve body. Anaccurately machined seat 82 is located on top of head 72 and encircleswell 80. An annular valve disc or wafer 84 of magnetizable materialhaving a face 86 accurately machined to coincide with the machined seat82 of body 68 is positioned on top of said seat and resiliently retainedthereon by spring 88. This disc may be of Permalloy or hypernik metalboth of which metals have high magnetic permeability and low residualmagnetism. A recess 85 in the top of disc 84 receives an end of spring88 and provides a means for limiting the lateral movement of disc 84 andinsures the complete coverage of seat 82 by disc face 86 at all timesthat said disc face is in contact with said seat. Since the maximumdistance of travel of the disc away from the seat 82 is approximatelyfive thousandths of an inch, the tendency of the disc to move laterallyis not great. As an additional precaution against too great alateralmovement of the disc, annular shoulder 83 partially defining recess 90in lower housing portion 62 is provided to abut the outer edge of disc84 should such lateral movement occur. It is anticipated that as analternative to the use of spring 88 and recess 85 as a means to preventthe lateral displacement of the disc, the annular shoulder 83 may beused exclusively.

,This free passage of fuel completely around the disc prevents theformation of a pressure difierential on the opposite surfaces of thedisc which would affect its controlled movement. A plastic ring 89secured to armature 96 provides a fluid tight, non-magnetic seal betweenretaining plate 108 and armature 96.

A solenoid 92 comprising a casing generally designated as "94 andarmature 96 is positioned within upper housing portion 60 and rests onshoulder 98 of lower housing portion 62. The solenoid casing 94comprises a cylindrical side portion 100, an integral top end portion.102 fitted into groove 104 of armature 96, a bottom flange 4 106, and abottom retaining plate 108 slidably fitted over the lower end ofarmature 96. Upper housing portion 60 is threadedly received in lowerhousing portion 62 by threads 110 and bears against flange 106 of thesolenoid housing 74 to thereby lock the solenoid assembly in positionwithin nozzle 58. Leads 112 and 114 of solenoid 92 extend throughapertures 116 and 118 respectively in casing 94 and are electricallyinsulated therefrom by bushings 120 and 122 respectively. Armature 96has a longitudinal spring receiving recess 124 located therein. Fluidinlet aperture 126 is located in the top of upper housing portion 60 andleads into chamber 128 which opens into chamber 130 through severalopenings located in flange 106 and retaining plate 108. The electricalcurrent 'used to actuate the fuel injection system is supplied by theautomotive battery or generator.

The solenoid housing portions 94, 96, 98, and 106 are of magnetizablematerial adapted to carry the magnetic field induced when solenoid 92 isenergized. The annular insulator 89 effects a gap in the magneticcircuit, which is bridged by the underlying wafer or valve disc 84. Inthis regard, the under surfaces of the members 89 and 108 are flush andparallel to the upper surface of the valve disc 84. Thus the disc 84 byvirtue of its broad area is eifective to carry an optimum proportion ofthe magnetic field and is substantially immediately responsive theretoin controlling fuel flow, as described below.

In FIGURE 4 is shown a variation in the structure of an injectionnozzlewhich is essentially comparable to that of FIGURE 1. This variation 198comprises a lower housing portion 200 having seated therein a portretaining plate 202 having spaced apertures 204 therethrough as shown inFIGURE 5 which is a sectional view along 5-5 of FIGURE 4. Mounted inapertures 204 are valve bodies 206 having flanges 208 thereon which abutretaining plate 202 and limit the extent of insertion of said valvebodies 206 therein. The fuel intake necks 210 of the bodies 206 aremachined across the top to place the tops of all the bodies 206 insubstantially a common plane. Restricted apertures 212 extend intoenlarged aperture 213 in each valve body- Mounted adjacent the peripheryof retaining plate 202 is a spring retaining ring 214 which interlockswith the valve disc return spring 216 by means of shoulders 218 and 220located1on the spring 216 and retaining ring 214 respectively. Valvedisc 222 having'a plane face 224 is normally urged into engagement withthe tops of bodies 206 to close the latter. Shoulders 226 and 228 ondisc 222 abut spring 216 on the bottom and inner edge thereof andprevent said disc from moving substantially in any direction exceptlongitudinally with respect to the injector nozzle 198.

An upper nozzle housing portion 230 is secured to portion 200 bycooperating groove 232 and indent 234 in the upper housing portion andlower housing portion respectively and by shoulder 238 and flange 236. Aring 240 positioned in said groove 232 insures a fluid tight sealbetween housing portions 200 and 230.

Integral with housing portion 230 is an armature 242 having a threadedfuel inlet connection 244 on one end thereof, a fuel outlet 246 at theother end thereof and a connecting fuel passage 248 therein. Mountedaround said armature is a solenoid coil 250 having leads 252 and 254extending through metal grommets 256 and 258 respectively located inapertures 260 and 262 in the upper nozzle housing 230. Suitable terminaltabs 264 and 266 are secured to the top of housing portion 240 by saidgrommets 256 and 258 respectively and are insulated from housing portion230 by insulation members 268 and 270 respectively. Grommets 258 and 256are hollow metal rivets which are spaced from the walls of apertures 260and 262 in housing portion 230. Insulating washers 274 and 272 insulatethe lower portions of grommets 256 and 258 respectively from housingportion 230. Leads 252 and 254 are soldered to their respectivegrommets. Insulative spool 276 carries the coil 250. A coil retainerplate 27 8 frictionally fitted into upper housing portion 230 holds coil250 in position within the nozzle housing. Spaced segments 280 of plate278 and rim 282 of armature 242 abut rims 288 and 284 respectively ofdisc 222 when the disc is magnetically pulled upwards from ports 206.

The operation of the nozzle of FIGURES l, 2, and 3 is as follows. Asupply of liquid fuel under substantially constant pressure is forcedinto the nozzle inlet 126 through fuel feed line 9. The fuel underpressure fills interstices 128, 132, 87, 30, 124, and 130. Seat 86 ofvalve disc 84 covers the fuel receiving well 80 in valve head 72 bylaying flat against the port seat 82. Spring 88 resiliently urges saiddisc against seat 82. When an electrical pulse is received by the nozzlesolenoid 92 from the triggering selector 22 the magnetic field producedby the solenoid pulls the disc 84 away from seat 82 against the weakerpressure of spring 88 and toward the end of the armature 96. The fuelunder pressure consequently flows into well 80 in valve head 72, outthrough the aperture 81 of the valve body 68 and into the vicinity ofthe engine intake valve port. When the electrical pulse as determined bythe modulator 44 ends, the solenoid 92 is deenergized and the spring 88forces the disc 84 back against valve seat 82 and stops further flow ofthe fuel into the port well 80.

The operation of the nozzle of FIGURE 4 is essentially the same. Thevariation in fuel flow is readily apparout, the flow being throughpassage 248, underneath disc 222, into the ports 206 and throughapertures 212 and 213 to the engine fuel intake system. It is noted thata free passage of fuel under pressure to both sides of the disc 222 isprovided in essentially the same manner as in the structure of thenozzle of FIGURE 2.

In both structures the actual distance that the disc 84 or 222 musttravel away from the ports in order to open the same and allow thenecessary fuel therethrough is very small and is measured in thousandthsof an inch. The length of time that the disc remains away from the portsis measured in milliseconds and is determined by the modulator currentpulse transmitted to the in jector solenoid by the triggering selector.Since the injector solenoid must become energized many times a secondwhen the engine is running at high speeds, the disc which the solenoidmust pull away from the valve ports must be of such a weight and shapeas to take best advantage of the short duration of the magnetic fieldproduced by the solenoid. The disc must respond instantaneously to thefield produced by the solenoid and must thereafter respondinstantaneously to the tension of the return spring 88 or 216 with aminimum susceptibility to residual magnetic forces when the solenoid isdeenergized.

I have determined that the best shape of the disc is substantially flat,one-half to three-quarters of an inch in diameter, and thirty to fortythousandths of an inch in thickness. When so shaped the disc is verylight and is immediately susceptible to the magnetic field of thesolenoid particularly since the relatively large surface area of thedisc is transverse to the plane of the greatest field force produced bythe solenoid. It is noted that any time lag in the response of the discto the induced field of the coil is detrimental to the timing of thefuel injection system and the resulting performance of the engine. Thistime lag is an important error factor since the total time that the discis normally in its port opening position during one flux cycle is in thevicinity of 0.5 millisecond.

While the preferred embodiments of the invention has been described andshown, it is understood that alterations and modifications may be madethereto, provided the said alterations and modifications fall within thescope of the appended claims.

What I claim is:

1. A post acting low inertia solenoid valve for controlling the flow offluids in relatively small quantities comprising a housing, a flowcontrol port therein, a freely shiftable valve disc having one sideengageable with said port to close the same, the edges of said discbeing spaced from said housing to enable limited and comparativelyfrictionless movement of said disc toward and away from said port, theother side of said disc being substantially flat and continuous, thespace between said disc and housing comprising conduit means for passageof fuel therethrough upon movement of sa d disc from said port, meansyieldingly urging said disc toward said valve port, said disc being of amagnetic material susceptible of being shifted from said port by amagnetic field, a plate of magnetic material having its peripheralportion secured to the inside of said housing and spaced from said disc,apertures in said plate forming part of said conduit means, and anelectrical coil in said housing having an armature extending throughsaid plate and spaced from said disc, said coil being spaced from theinside of said housing to form part of said conduit means.

2. In a liquid fuel control system for an internal combustion engine,fluid conduit means adapted for connecting an engine with a source ofliquid fuel, a hollow valve housing comprising a part of said conduitmeans and having a valve port, a freely shiftable valve disc having oneside engageable with said port to close the same, the edges of said discbeing spaced from said housing to enable limited and comparativelyfrictionless movement of said disc toward and away from said port, theother side of said disc being substantially fiat and continuous, thespace between said disc edges and housing comprising part of saidconduit means for passage of fuel therethrough upon movement of saiddisc from said port, means yieldingly urging said disc toward said valveport, said disc being of a magnetic material susceptible of beingshifted from said port by a magnetic field, a plate of mag neticmaterial having its peripheral portion secured to the inside of saidhousing and spaced from said disc, apertures in said plate forming partof said conduit means, and an electrical coil in said housing having anarmature extending through said plate and spaced from said disc, saidcoil being spaced from the inside of said housing to form part of saidconduit means.

3. In a liquid fuel control system for an internal combustion engine,fluid conduit means adapted for connecting an engine with a source ofliquid fuel, a hollow valve housing comprising a part of said conduitmeans and having a valve port, a freely shiftable valve disc having oneside engageable with said port to close the same upon movement of saiddisc, the edges of said disc being spaced from said housing to enablelimited and comparatively frictionless movement of said disc toward andaway from said port, the other side of said disc being substantiallyfiat and continuous, the space between said disc edges and housingcomprising part of said conduit means for passage of fuel therethroughupon movement of said disc from said port, means yieldingly urging saiddisc toward said valve port, said disc being of a magnetic materialsusceptible of being shifted from said port by a magnetic field, a plateof magnetic material having its peripheral portion secured to the insideof said housing and spaced from said disc, apertures in said plateforming part of said conduit means, an electrical coil in said housinghaving an armature extending through said plate and spaced from saiddisc, said coil being spaced from the inside of said housing to formpart of said conduit means, and electrical insulating means interposedbetween said metal plate and said armature for preventing shunting ofmagnetic flux away from said disc.

(References on following page) References Cited in the file of thispatent UNITED STATES PATENTS Bickley Feb. 26, 1957 10 8 Hales Apr.1,1958 Ray June 10, 1958 Rhodes Nov. 18, 1958 Beck Apr. 4, 1959 GunkelOct. 27, 1959 Nickells Ian. 26, 1960 OTHER REFERENCES SAE Journal, April1957, pp. 26-29 (123439.17).

UNITED STATES PATENT OFFICE CERTIFICATE OF CQRRECTION Patent No3,001,757 I I September 26, 1961 Thomas M. Ball It is hereby certifiedthat error appears in {the above numbered patentrequiring correction andthat the said Letters Patent should read as "corrected below.

Column 2, line 541: before "through" insert 52 column 3, line 56 for"formed" read forced column 4, line 68, for "240" read 230 column 5 line15, for "lpying" read lying column 6, line 13, before "and" insert edgesSigned and sealed this 6th day of March 1962.

(SEAL) Attest:

ERNEST w. SWIDER' DAVID L. LADD Attesting Officer Commissioner ofPatents

